Decoupling Control of Bi-copter UAV with Centroid Bias

• 1、School of Automation, Guangdong University of Technology, Guangzhou

Abstract：Aiming at the problem that traditional attitude controllers for Bi-copter UAV have difficulty in dealing with the nonlinear coupling caused by the centroid bias, a decoupling controller was proposed. Firstly, the dynamic models of the Bi-copter UAV with and without centroid bias are established, and a decoupling control algorithm is designed based on the model when the centroid position is known. Then, to estimate the position of centroid, a centroid bias angle observer is designed. Finally, based on the traditional attitude controller, the decoupling algorithm is embedded to achieve decoupling of each control channel. Linear model of the drone is established under small angle approximation and the distribution of the closed loop poles as well as the dynamic performance and stability of the control system was estimated through root-locus. Simulation results showed that the estimation of centroid bias angle were stable and accurate, compared with the PD controller without decoupling, the proposed controller could reduce the attitude control error by 25.3\% under centroid bias. In actual flight tests, the accuracy of the roll angle control was about 0.5 degree, and the control error of the pitch and yaw angle were less than 2.5 degree.

Keywords： Bi-copter UAV centroid bias decoupling control attitude control